Dental apparatus

ABSTRACT

A dental apparatus having a disposable nozzle tip ( 11 ) for a three-way syringe device ( 12 ) for spraying air or water. The nozzle tip ( 11 ) comprises an assembly of two coaxial tubes ( 20, 21 ) which can be readily attached/detached from the syringe device ( 12 ), such attachment can be effected directly or via an adaptor ( 26 ) which allows the nozzle tip ( 11 ) to be connected to a number of different devices. The nozzle tip ( 11 ) is constructed from a plastics material which facilitates disposability.

This application was the National Stage of International Application No.PCT/GB89/00972, filed Aug. 21, 1989, which claimed priority of GreatBritain patent application Ser. No. 8900896.5, filed Jan. 16, 1989.

TECHNICAL FIELD

This invention relates to dental apparatus, and in particular to syringeapparatus for providing a jet of air, liquid or air/liquid mixture to apatient undergoing dental treatment.

BACKGROUND ART

Such three-ay syringe apparatus is used for cleaning the mouth of dustand small particles of tooth or filling material after drilling,grinding, scraping or the like. The apparatus comprises a hand-heldappliance to which a supply of air and a supply of water, both underpressure, are supplied, and has a nozzle assembly or nosel tip at theoperating end thereof. Such nozzle assembly or nosel tip comprises acoaxial tube assembly which is secured on the end of the three-waysyringe apparatus. Both inner and outer tube of the nosel tip are ofmetal, for example brass, stainless steel, anodised aluminum or thelike, and since the inner tube must be supported within the outer tubewhilst allowing flow through the outer tube, the nosel tip is relativelycostly to produce. Although the three-way syringe apparatus is notactually intended to come into contact with the patient's mouth,inevitably such contact does occur from time to time since the nosel tipmust be placed within the mouth in order that the jet can be directed tothe required location. Consequently it is possible for the nosel tip atleast to become contaminated during use. Conventionally, the dentist ofthe dental assistant will clean the nosel tip, after use of the syringedevice, by means of cleaning fluid. However, this is not a whollysatisfactory method of ensuring that the nosel tip is contamination-freefor the next use. Alternatively, the nosel tip could be removed andautoclaved, but this is a time-consuming operation which is frequentlynot carried out.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a dental apparatusof the above described type whereby it is possible to ensure that acontamination-free apparatus is available for each occasion of use.

The invention provides a dental apparatus comprising a nosel tip for athree-way syringe device, the nosel tip comprising a co-axial tubeassembly having attachment means adapted for releasable attachment ofthe nosel tip to a syringe device, wherein at least an outer tube ofsaid co-axial tube assembly is of a plastics material.

By means of the invention the nosel tip can be cheaply produced so thateach nosel tip may be removed from the syringe device after use on onepatient and discarded, so that a new uncontaminated nossel tip can beattached to the syringe device for use on the next patient. In this way,the risk of cross-infection between patients is avoided or at leastsubstantially reduced.

An inner tube of said coaxial tube assembly may be of metal, for examplebrass, stainless steel or anodised aluminum. Alternatively the innertube may also be of a plastics material. The outer tube may be mouldedonto the inner tube. The nosel tip may have a cap part which may besecured to or integral with said outer tube and said cap part may havethe attachment means formed thereon. Said attachment means may comprisea screw-thread provided internally of the cap part or may comprisebayonet or catch receiving means. The apparatus may also comprise anadaptor, disposed between said nosel tip and syringe device, the adaptorallowing attachment of said nosel tip to the device. Thus in the casewhere an adaptor is present, it is possible for the same nosel tip to befitted to different syringe devices by the use of different adaptors,said adaptor may have a cap part with a screw-thread attachment meansprovided internally thereof, and a screw-thread for engagement with thenosel tip or a bayonet or catch means adapted to be received in bayonetor catch receiving means on the nosel tip.

The adaptor may be arranged to cooperate with the nosel tip via securingmeans, the securing means providing a leak-proof connection between thenosel tip and adaptor. Preferably the adaptor has a recess therein inwhich one end of said securing means locates. In this case a seal may beprovided to secure and seal the end of said securing means in therecess. The seal may be an ‘O’ ring or rubber seal or the like. Theother end of said securing means may have a plurality of flangesextending radially outward thereof, the flanges locating in groovesprovided in said nosel tip. Preferably there are four such flangesspaced angularly by 90° around the outer surface of said other end ofthe securing means.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described with reference to the accompanyingdrawings, in which:

FIG. 1 is an elevation of a first embodiment;

FIG. 2 is an exploded elevation of a second embodiment; and

FIG. 3 is a sectional side view of part of a third embodiment showingthe region of connection between the adaptor and the nosel tip.

BEST MODES FOR CARRYING OUT THE INVENTION

Referring now to FIG. 1 there is shown a dental apparatus 10 comprisinga nosel tip 11 for a three-way syringe device 12. The syringe device 12comprises a body 13 which is connected to a flexible coaxial pipearrangement 14, itself connected to sources (not shown) of air and waterunder pressure. Two levers 15, 16 are provided on the body 13 and areoperable to allow flow of air, water or air and water through theapparatus 10. The syringe device 12 has a head 17 which is provided witha male screw-threaded portion 18, and the nosel tip 11 has a cap part 19having an internal screw-thread (not shown), by means of whichscrew-threads the nosel tip 11 can be removably attached to the head 17.

The nosel tip 11 comprises an inner tube 20 and an outer tube 21 whichform a coaxial tube assembly from the cap part 19 to the twin jet end22. The inner tube 20 extends beyond the cap part 19 so as to besealingly received in a co-operating inner tube 23 of the head 17. Thisensures that there is no back flow of one fluid medium down the supplypipe of the other fluid medium when the latter is not being used.

The inner tube 20 may be of any suitable material such as brass,stainless steel or anodised aluminium, or a plastics material. However,the outer tube 21 is of a plastics material and may be moulded,integrally with the cap part 19, onto the inner tube 20. By this meansthe nosel tip 11 can be inexpensively produced so that it can bediscarded after use of the apparatus 10 on one patient to reduce therisk of cross-inflection of a subsequent patient. A new uncontaminatednosel tip 11 is readily attached to the head 17 for use of the apparatus10 on another patient.

As an alternative to the cap part 19 being provided with an internalscrew thread, it may be provided with bayonet receiving means 24 in theform of one or more L-shaped slots as shown in FIG. 2. In all otherrespects the nosel tip 11 shown in FIG. 2 is identical with that shownin FIG. 1. The head 17 of the syringe device 12 may be provided withbayonets 25 adapted to be received in the bayonet receiving means 24 ofthe nosel tip 11. Alternatively, as shown in FIG. 2, the head 17 may beprovided with the conventional male screw-threaded portion 18 and anadapter 26 is provided. The adaptor 26 has bayonets 25 thereon and aninternally screw-threaded cap part 27 so that it may be attached to aconventional syringe device 12 and the nosel tip 11 may be readilyattached and removed from the adaptor 26 by cooperation of the bayonets25 and the bayonet receiving slots 24. Other readily separableattachment means will be readily apparent to persons skilled in the art.For example, bayonets 25 and slots 24 may be replaced by a radiallyoutward spring loaded catch which is received in an aperture oroutwardly directed recess in the cap part 19, or an internal bore of thecap part 19 may be dimensioned so that the cap part is simply a push fiton a shoulder of the adaptor 26.

A further alternative is shown in FIG. 3 in which a securing means 30 isused to locate an adapter 31 generally similar to that shown as 26 inFIG. 2, relative to the inner tube 20 of the nosel tip 11. The securingmeans is of the form of a stepped hollow body 30 having a stepped bore33 thereto. In the embodiment shown the body 30 is a generallycylindrical form, however other shapes may be used as appropriate. Bothends 34 and 35 of the body 30 are tapered to allow easy fitting of thestructure. A number of flange structures 36 protrude radially outwardlyfrom the enlarged part 37 of the body 30 which locate in internalgrooves (not shown) in the outer tube 21, fixing the two parts relativeto each other. Preferably four such flanges 36 protrude from the body 30and are spaced angularly by 90°. The reduced part 38 of the body 30 isarranged to cooperate with a recess 39 in the adaptor 31 in any suitablemanner, for example by a push fit and is sealed therein by way of seal41.

The adaptor comprises a stepped inner retaining structure 45 having astepped axial bore 47 and an outer sleeve 46 formed integrallytherewith. The recess 39 is provided in a part 48 of the structure 45and is arranged to engage with the inner tube 20 via the securing means30 in sealing relationship thereto providing a continuous bore for theflow of fluid. The outer sleeve 46 has internal screw-threads 42 on oneend 43 thereof which engage with corresponding screw-threads 44 on theexternal surface of the nosel tip 11, providing a further continuousbore between the inner retaining structure 45 and the outer sleeve 46.

With this arrangement it is possible to provide a nosel tip which isboth hygienic in that it is readily removable and disposable and can befitted securely to the apparatus.

It is of course to be understood that the invention is not intended tobe restricted to the details of the above embodiment which are describedby way of example only.

What is claimed is:
 1. Dental apparatus comprising a syringe tip for a three-way syringe device having a connector for attachment thereto of said tip, said tip comprising a coaxial assembly of an inner tube and an outer tube and having thereon attachment means adapted for releasable attachment of said tip to said syringe device by interlocking interengagement of said attachment means with a cooperable structure, wherein an adaptor is provided with said cooperable structure thereon whereby said attachment means is adapted for said releasable attachment via said adaptor disposed between said tip and said connector of said syringe device, and that said outer tube of said coaxial tube assembly is of plastics material and said inner tube of said coaxial assembly is of metal, whereby said tip is formed as a removable and disposable part.
 2. Dental apparatus comprising a syringe tip for a three-way syringe device having a connector for attachment thereto of said tip, said tip comprising a coaxial assembly of an inner tube and an outer tube and having thereon attachment means adapted for releasable attachment of said tip to said syringe device by interlocking interengagement of said attachment means with a cooperable structure, wherein an adaptor is provided with said cooperable structure thereon whereby said attachment means is adapted for said releasable attachment via said adaptor disposed between said tip and said connector of said syringe device, and that at least said outer tube of said coaxial tube assembly is of plastics material, whereby said tip is formed as a removable and disposable part; and said adaptor is arranged to cooperate with said tip via securing means, said securing means providing a leak-proof connection between said tip and said adaptor wherein the other end of said securing means has a plurality of flanges extending radially outward thereof, said flanges locating in corresponding grooves provided in said nozzle tip.
 3. Apparatus according to claim 2 wherein said other end of said securing means is provided with four of said plurality of flanges spaced angularly by 90 degrees around its external periphery.
 4. Dental apparatus comprising a syringe tip for a three-way syringe device having a connector for attachment thereto of said tip comprising a coaxial assembly of an inner tube and an outer tube and having thereon a cap part with attachment means adapted for releasable attachment of said tip to said syringe device by interlocking interengagement of said attachment means with a cooperable structure, said inner tube extending into said cap part and said cap part being formed integrally with said outer tube, wherein an adaptor is provided with said cooperable structure thereon whereby said attachment means is adapted for releasable attachment via said adaptor disposed between said tip and said connector of said syringe device with said cap part and inner tube engaged with said adaptor, and that at least said outer tube of said coaxial tube assembly is of plastics material, whereby said tip is formed as a removable and disposable part.
 5. Apparatus according to claim 4 wherein said inner tube is fabricated from plastics material.
 6. Apparatus according to claim 4 wherein said outer tube is molded onto said inner tube.
 7. Apparatus according to claim 4 wherein said cap part has said attachment means formed thereon.
 8. Apparatus according to claim 4 wherein said attachment means comprises a screw-thread provided internally of said cap part.
 9. Apparatus according to claim 4 wherein said attachment means comprises bayonet or catch receiving means.
 10. Apparatus according to claim 4 wherein said adaptor is arranged to cooperate with said tip via securing means, said securing means providing a leak-proof connection between said tip and adaptor.
 11. Apparatus according to claim 10 wherein said adaptor has a recess therein, in which one end of said securing means locates.
 12. Apparatus according to claim 11 wherein said one end of said securing means is retained within said recess by way of a seal.
 13. Apparatus according to claim 12 wherein said seal comprises an ‘O’ ring.
 14. Apparatus according to claim 10 wherein the other end of said securing means has a plurality of flanges extending radially outward thereof, said flanges locating in corresponding grooves provided in said nozzle tip.
 15. Apparatus according to claim 14 wherein said other end of said securing means is provided with four said flanges spaced angularly by 90° around its external periphery. 